JP3246538U - Extendable support legs - Google Patents

Abstract

[Problem] To provide an extendable support leg which has a good locking effect between three leg tubes, does not require fasteners protruding from the outside of the leg tubes, is less likely to cause erroneous contact, and is easy to store. [Solution] The present invention includes a front leg tube, a middle leg tube, a rear leg tube, a first clamp mechanism located between the front leg tube and the middle leg tube, and a second clamp mechanism located between the middle leg tube and the rear leg tube, the lock control mechanism 6 includes a lock ring fitted and connected to an upper end of the front leg tube, and a transmission shaft connected to the lock ring and having one end inserted into the front leg tube, the lock ring rotates in a circumferential direction to rotate the transmission shaft about its own axial direction, the transmission shaft is operably connected to the first clamp mechanism to releasably prevent the movement of the middle leg tube relative to the front leg tube, and the transmission shaft is operably connected to the second clamp mechanism to releasably prevent the movement of the rear leg tube relative to the middle leg tube. [Selected Figure] Figure 1

Description

This invention relates to the technical field of photographic equipment, and specifically to extendable support legs.

The camera support legs include tripods and monopods, and the tripod and monopod support legs have three leg tubes with different diameters, which are slidable relative to each other, thereby changing the length of the support legs. When the support legs are at a required length, any two adjacent leg tubes are locked. In a typical support leg telescopic structure, the locking mechanism between two adjacent leg tubes needs to be locked or unlocked in stages, which is relatively cumbersome to operate.

In conventional technology, there are support legs that use a single fastener to synchronously lock or unlock multiple leg tubes, but in structures that use a single fastener to lock, the locking effect of the entire support leg is relatively poor and loosening is likely to occur when the support leg bears a relatively large weight. In addition, the part of the fastener that protrudes outward from the support leg body is relatively long, making it easy for the fastener to come into contact with the multiple leg tubes accidentally during use, resulting in the locking of the multiple leg tubes. Therefore, it is necessary to design a locking structure for the support leg that provides a more stable locking effect.

Therefore, the technical problem that this invention must solve is to provide an extendable support leg by overcoming the drawbacks of the conventional method of using a single fastener to control multiple leg tubes of a support leg to achieve synchronous locking, which has poor locking effect and is prone to being released by erroneous contact with the fastener.

To solve the above technical problems, the technical proposal of this invention is as follows:

an extendable support leg including a front leg tube, a middle leg tube, and a rear leg tube that are arranged in order from the outside to the inside and are extendable and contractable in the axial direction, the support leg further including a first clamp mechanism attached between the front leg tube and the middle leg tube, and a second clamp mechanism installed between the middle leg tube and the rear leg tube;
The lock control mechanism includes a lock ring that is fitted and connected to the upper end of the front stage leg pipe and is installed to rotate circumferentially on the front stage leg pipe, and a transmission shaft that is connected to the lock ring in a transmission manner and has one end inserted into the front stage leg pipe, and when the lock ring rotates circumferentially relative to the front stage leg pipe, the lock ring rotates the transmission shaft about its axial direction, the transmission shaft is operably connected to a first clamp mechanism so as to releasably prevent movement of the middle stage leg pipe relative to the front stage leg pipe, and the transmission shaft is operably connected to a second clamp mechanism so as to releasably prevent movement of the rear stage leg pipe relative to the middle stage leg pipe.

Furthermore, a lower base is fixedly connected to the upper end of the front leg pipe, and the transmission shaft rotates in the circumferential direction and is fixedly connected to the lower base in the axial direction.

Furthermore, the lock ring rotates in the circumferential direction and is fixedly connected to the lower base in the axial direction.

In addition, a stepped structure is provided on the outer periphery of the upper end of the lower base, and an inner convex structure that fits into the stepped structure is provided on the inner wall of the lock ring.

Furthermore, the lock ring and the transmission shaft are connected for transmission via gear meshing.

Furthermore, the lock ring is connected to the transmission shaft via a gear transmission assembly.

Furthermore, an upper cover is fixedly connected above the lower base, and the gear transmission assembly is a planetary gear assembly, which includes a sun gear that is rotatably installed in the center hole of the lower base, a plurality of planetary gears that are located between the upper cover and the lower base and are connected to the outer periphery of the sun gear through gear meshing, and a ring gear that is located on the outer periphery of the plurality of planetary gears and meshes with the plurality of planetary gears to transmit power, the transmission shaft is fixedly connected to the gear shaft of the sun gear and is installed coaxially with the gear shaft of the sun gear, and the lock ring is fixedly mounted on the outer periphery of the ring gear.

Furthermore, the ring gear is fixedly connected to the upper part of the inner convex structure.

In addition, an anti-slip sleeve is fitted to the outer wall of the lock ring, and an anti-slip structure is provided on the outer periphery of the anti-slip sleeve.

Furthermore, the first clamp assembly includes a transmission tube, an upper locking member, a locking body, and an expansion member, the transmission tube is connected to the outer periphery of the transmission shaft and maintains circumferential fixation and axial sliding with the transmission shaft, the locking body is fixedly connected to the middle leg tube and screwed to the outer periphery of the transmission tube, the upper locking member is fixedly connected to the outer periphery of the upper end of the transmission tube, the expansion member is axially fixed to the locking body and is located on the outer periphery of the upper locking member, and the expansion member has a tightened state in which it expands outward under the action of the upper locking member to tighten the inner wall of the front leg tube, and a loosened state in which it narrows inward and moves away from the inner wall of the front leg tube.

Furthermore, the cross section of the transmission shaft and the cross section of the transmission tube are the same, and both cross sections are non-circular.

Furthermore, the upper locking member includes a tapered step having an outer tapered inclined surface, and the expansion member includes at least two mutually independent expansion blocks, the inner wall of the expansion block has an inner tapered inclined surface, and the outer tapered inclined surface and the inner tapered inclined surface are engaged with each other.

Furthermore, an elastic kit is provided on the outer periphery of at least two of the expansion blocks, and the elastic kit applies an inward narrowing force to the at least two expansion blocks.

Furthermore, an inner friction plate is provided on the outer wall of the expansion member to abut against the inner wall of the front leg pipe.

Furthermore, the second clamping mechanism includes an inner tube that is fixedly connected to the transmission pipe in the axial direction and located inside the middle leg pipe, a lock sleeve that is connected to the end of the inner tube away from the transmission pipe and located inside the middle leg pipe, and an elastic sleeve that is fitted around the outer periphery of the rear leg pipe and partially inserted into the lock sleeve and fixed to the middle leg pipe in the axial direction. When the lock sleeve and the elastic sleeve move in the axial direction, the elastic sleeve has a clamped state in which it narrows inward under the action of the lock sleeve and is clamped to the outer wall of the rear leg pipe, and an unlocked state in which it moves away from the lock sleeve to unlock the rear leg pipe.

Furthermore, an inner inclined guide surface is provided on the inner wall of the lock sleeve, and an outer inclined guide surface is provided on the outer wall of the elastic sleeve, and the inner inclined guide surface and the outer inclined guide surface are fitted together.

Furthermore, a connection sleeve is fixedly connected to the outer wall of the lower end of the middle leg tube, an adjustment sleeve is screwed to the outer periphery of the connection sleeve, and the elastic sleeve is fixedly connected to the adjustment sleeve in the axial direction.

Furthermore, a notch is provided in the side wall of the elastic sleeve, and the notch extends from the center of the side wall to the end of the side wall of the elastic sleeve.

Furthermore, a first anti-slip structure is provided between the front leg pipe and the middle leg pipe to prevent the middle leg pipe from sliding out of the front leg pipe, and a second anti-slip structure is provided between the inner pipe and the rear leg pipe to prevent the rear leg pipe from sliding out of the inner pipe.

The technical solution of this invention has the following advantages:

1. The extendable support leg of the present invention has a lock control mechanism consisting of a lock ring and a transmission shaft installed at the upper end of the front leg tube. One end of the transmission shaft is inserted into the front leg tube and connected to the first clamp mechanism and the second clamp mechanism. When the length of the support leg is adjusted, the lock ring is rotated in one direction, and the lock ring rotates the transmission shaft in the forward direction around its own axial direction, transmitting the forward rotation of the transmission shaft to the first clamp mechanism and the second clamp mechanism, so that the first clamp mechanism releases the movement of the middle leg tube relative to the front leg tube, and the second clamp mechanism releases the movement of the rear leg tube relative to the middle leg tube. When the length of the support leg is adjusted to the required length, the lock ring is rotated in the opposite direction. The lock ring is rotated to rotate the transmission shaft in the opposite direction, and the reverse rotation of the transmission shaft is transmitted to the first clamp mechanism and the second clamp mechanism, so that the first clamp mechanism prevents the middle leg tube from moving relative to the front leg tube, and the second clamp mechanism prevents the rear leg tube from moving relative to the middle leg tube, thereby realizing the adjustment of the length of the support legs. Compared to the conventional method of adjusting the length of the support legs using fasteners, the method of rotating the transmission shaft with the lock ring not only has a good locking effect between the three leg tubes of the support legs, but also eliminates the need for fasteners protruding from the outside of the leg tubes, making it less likely to cause miscontact and making it easier to store the support legs.

In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings that need to be used in the embodiments of the present invention or the prior art description. It is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings based on these drawings without exerting creative efforts.
2 is a schematic diagram of the structure of a tripod according to an embodiment of the present invention; 4 is a schematic diagram of the structure of one support leg in the embodiment of the present invention; FIG. 2 is a structural schematic diagram of a lock control mechanism according to an embodiment of the present invention. FIG. 2 is a structural schematic diagram of a first clamping mechanism according to an embodiment of the present invention. FIG. 2 is a structural schematic diagram of a first anti-slip structure in an embodiment of the present invention. FIG. 4 is a structural schematic diagram of a second clamping mechanism according to an embodiment of the present invention. FIG. 4 is a structural schematic diagram of a second anti-slip structure in an embodiment of the present invention.

The following clearly and completely describes the technical solution of the present invention in conjunction with the drawings. Obviously, the described embodiments are only some of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without exerting creative efforts are all within the scope of protection of the present invention.

In describing the present invention, it should be explained that the orientations or positional relationships indicated by the terms "center," "up," "down," "left," "right," "vertical," "horizontal," "inside," "outside," etc. are orientations or positional relationships shown based on the drawings, and are intended only to facilitate and simplify the description of the present invention, and do not indicate or imply that the devices or elements referred to have a particular orientation, or must be configured and operated in a particular orientation, and should not be understood as limiting the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance.

In the description of the present invention, it should be explained that unless otherwise clearly defined or limited, the terms "attached," "connected," and "connected" should be understood in a broad sense, and may refer to, for example, a fixed connection, a removable connection, an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intermediate medium, or internal communication between two elements. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

The present invention discloses an extendable support leg, which may be a tripod with three legs or a single leg. Taking a camera tripod as an example, FIG. 1 shows a perspective structural view of a camera tripod, which includes a tripod head element 20 located at the top of the tripod and three support legs 10, each of which is rotatably connected to the head element 20, and these three support legs are the extendable support legs which claim protection in this application.

Figure 2 shows a perspective structural view of the support leg 10, which includes a front leg tube 1, a middle leg tube 2, and a rear leg tube 3, which are installed in order from the outside to the inside and are axially extendable and retractable, and a lock control mechanism 6 is connected to the top end of the front leg tube 1. Inside the support leg 10, there is a first clamp mechanism (not shown in Figure 2) installed between the front leg tube 1 and the middle leg tube 2, and a second clamp mechanism (not shown in Figure 2) installed between the middle leg tube 2 and the rear leg tube 3.

Figure 3 shows a schematic diagram of the internal structure of the lock control mechanism 6, which includes a lock ring 61, a transmission shaft 62, a gear transmission assembly, a lower base 64, and an upper cover 65.

Here, the lower base 64 is fixedly connected to the upper end of the front leg pipe 1, the lower half of the lower base 64 is fitted to the outer periphery of the upper end of the front leg pipe 1, the upper half of the lower base 64 abuts against the end of the upper end of the front leg pipe 1, and a central hole is provided in the center of the upper half of the lower base 64. The lock ring 61 and the transmission shaft 62 both rotate in the circumferential direction and are fixedly connected to the lower base 64 in the axial direction. A step structure is provided on the outer periphery of the upper half of the lower base 64, and an inner protruding structure 611 that fits into the step structure is protruded from the inner wall of the lock ring 61. The upper cover 65 is fixed above the lower base 64 via multiple bolts.

In some embodiments, the gear transmission assembly is specifically a planetary gear assembly located at a spaced position between the lower base 64 and the upper cover 65, and the tip assembly 9 for connecting to the head element 20 of the support leg 10 is placed above the upper cover 65 and fixedly connected to the upper cover 65. The planetary gear assembly includes a sun gear 631 located at the center, three planetary gears 632 that are connected to the outer periphery of the sun gear 631 through gear meshing, and a ring gear (not shown) that is located on the outer periphery of the three planetary gears 632 and meshes with the three planetary gears 632 to transmit. The gear shaft of the sun gear 631 passes through a central hole of the lower base 64 and is rotatably connected to the lower base 64 through a bearing, the gear shafts of the three planetary gears 632 are connected between the lower base 64 and the upper cover 65, and the ring gear is located between the lower base 64 and the upper cover 65. A shim is interposed between the upper end of the ring gear and the lower end surface of the upper cover 65 to reduce friction when the two rotate relative to each other. In alternative embodiments, the lock ring 61 is directly meshed with the tooth structure on the outer periphery of the transmission shaft 62 via the tooth structure on the inner side wall, or the ring gear is fixedly connected to the inner side wall of the lock ring 61, and the ring gear is meshed with the tooth structure on the outer periphery of the transmission shaft 62 to connect.

In this embodiment, the transmission shaft 62 is fixedly connected to the gear shaft of the sun gear 631 and is installed coaxially with the gear shaft of the sun gear 631, and one end of the transmission shaft 62 is inserted into the front leg tube 1. The lock ring 61 is fixedly fitted to the outer periphery of the ring gear, and the inner diameter of the lock ring 61 is larger than the outer diameter of the front leg tube 1, and the lower half of the upper cover 65, the outer side of the ring gear, and the outer side of the lower base 64 are all covered by the lock ring 61. When the lock ring 61 rotates in the circumferential direction relative to the front leg tube 1, the lock ring 61 rotates the transmission shaft 62 about its own axial direction via the planetary gear assembly, and the transmission shaft 62 is operably connected to the first clamp mechanism 4 so as to releasably prevent the movement of the middle leg tube 2 relative to the front leg tube 1, and the transmission shaft 62 is operably connected to the second clamp mechanism 5 so as to releasably prevent the movement of the rear leg tube 3 relative to the middle leg tube 2.

In some embodiments, the lower end of the ring gear is secured to the inner convex structure 611, thereby ensuring that the lock ring 61 rotates the ring gear. A shim is also provided between the lower end of the inner convex structure 611 and the lower base 64 to reduce friction when the two rotate relative to one another.

In some embodiments, the lock ring 61 has grooves on both the upper and lower sides of its outer wall, anti-slip sleeves 66 are fitted in the two grooves, and the anti-slip structure is provided on the outer periphery of the anti-slip sleeve 66, specifically an anti-slip screw. The installation of the anti-slip sleeve 66 makes it easier to rotate the lock ring 61 by hand. Gaskets are provided at the contact position between the upper inner wall of the lock ring 61 and the outer wall of the upper cover 65, and at the contact position between the lower inner wall of the lock ring 61 and the outer wall of the lower base 64 to reduce friction during relative rotation.

In some embodiments, the transmission shaft 62 is a hollow tubular structure to reduce the overall weight of the support leg 10.

Figure 4 shows a schematic diagram of the structure of the first clamp assembly, which includes a transmission tube 41, an upper locking member 42, a locking body 43, and an expansion member 44. The transmission shaft 62 and the transmission tube 41 both have non-circular cross sections. In this embodiment, the transmission shaft 62 and the transmission tube 41 both have rectangular cross sections. The size of the inner diameter cross section of the transmission tube 41 is the same as the size of the outer diameter cross section of the transmission shaft 62, the transmission tube 41 is fitted to the outer periphery of the transmission shaft 62, the transmission tube 41 is fixed in the circumferential direction and slides in the axial direction with the transmission shaft 62, and a male thread structure is provided on the outer periphery of the middle part of the transmission tube 41. The lock body 43 is fixedly connected to the middle leg tube 2 and screw-connected to the outer periphery of the power transmission tube 41. The lock body 43 includes a lock fixing sleeve fixedly connected to the end of the middle leg tube 2 and a lock sleeve fixed to the lock fixing sleeve and having a female thread structure, and the male thread structure of the power transmission tube 41 and the female thread structure of the lock sleeve are screw-fitted. The upper lock member 42 is fixedly connected to the outer periphery of the upper end of the power transmission tube 41, and the lower end of the upper lock member 42 extends outside the lock sleeve of the lock body 43. The expansion member 44 is axially fixed to the lock body 43 and located on the outer periphery of the upper lock member 42. The upper lock member 42 includes a tapered step having an outer tapered inclined surface, and the expansion member 44 includes a plurality of mutually independent expansion blocks, the inner wall of the expansion block has an inner tapered inclined surface, and the outer tapered inclined surface fits into the inner tapered inclined surface. When the lock ring 61 rotates the transmission shaft 62 in the forward direction, the transmission shaft 62 drives the rotation of the transmission tube 41, and due to the screw-fitting action between the transmission tube 41 and the lock body 43, the transmission tube 41 moves downward, and the upper locking member 42 fixedly connected to the transmission tube 41 also moves downward. When the upper locking member 42 moves downward, it presses the expansion member 44 due to the inclined surface action, and the expansion member 44 expands outward under the pressing action of the upper locking member 42 to tighten the inner wall of the front leg tube 1, thereby locking the front leg tube 1 and the middle leg tube 2. Conversely, when the lock ring 61 rotates the transmission shaft 62 in the opposite direction, the transmission tube 41 moves upward, and the upper locking member 42, which is fixedly connected to the transmission tube 41, also moves upward. When the upper locking member 42 moves upward, it unlocks the expansion member 44, which narrows inward, and the front leg tube 1 and the middle leg tube 2 move apart, thereby unlocking the front leg tube 1 and the middle leg tube 2.

In some embodiments, annular grooves are provided at both the upper and lower ends of the outer periphery of the multiple expansion blocks, and elastic kits 45 are installed in both of the two annular grooves. The elastic kits 45 apply an inward narrowing force to the multiple expansion blocks, and the installation of the elastic kits 45 can prevent the expansion blocks from loosening and provide the expansion blocks with an elastic movable space.

In some embodiments, the outer wall of the expansion block is provided with an internal friction plate 46 for abutting against the inner wall of the front leg pipe 1. The installation of the internal friction plate 46 can reduce rotational wear between the expansion block and the front leg pipe 1, and when the internal friction plate 46 becomes too worn, it can be replaced to maintain the original condition.

Figure 5 shows a schematic diagram of the structure of the first anti-slip structure 7. Between the front leg tube 1 and the middle leg tube 2, the first anti-slip structure 7 is provided to prevent the middle leg tube 2 from sliding out of the front leg tube 1. Specifically, the first anti-slip structure 7 is an anti-slip sheet located on the inner wall at the lower end of the front leg tube 1.

Figure 6 shows a schematic diagram of the structure of the second clamp mechanism 5, which includes an inner tube 51, a lock sleeve 52, and an elastic sleeve 53, and the inner tube 51 is located inside the middle leg tube 2. Referring to Figure 4, a pair of stopper rotating disks 57 are fixedly connected to the lower end of the transmission tube 41, and a stopper groove is formed on the outer periphery of the pair of stopper rotating disks 57. A connecting member 56 is fixedly connected to the upper end of the inner tube 51, and the upper end of the connecting member 56 is fitted into the stopper groove so that the connecting member 56 and the transmission tube 41 are fixed in the axial direction but can rotate in the circumferential direction. The transmission tube 41 can move the inner tube 51 up and down via the pair of stopper rotating disks 57 and the connecting member 56, and the inner tube 51 can rotate in the circumferential direction relative to the transmission tube 41. 6, the lock sleeve 52 is fixedly connected to the lower end of the inner tube 51 remote from the transmission tube 41, the elastic sleeve 53 is fitted around the outer periphery of the rear leg tube 3 and partially inserted into the inside of the lock sleeve 52, and the elastic sleeve 53 is axially fixed to the middle leg tube 2. An inner wall of the lock sleeve 52 is provided with an inner inclined guide surface, and an outer wall of the elastic sleeve 53 is provided with an outer inclined guide surface, and the inner inclined guide surface and the outer inclined guide surface are fitted together. When the outer inclined guide surface of the outer wall of the elastic sleeve 53 is pressed by the inner inclined guide surface of the lock sleeve 52, the elastic sleeve 53 narrows inward under the pressing force of the lock sleeve 52, clamping the outer wall of the rear leg tube 3, thereby locking the middle leg tube 2 and the rear leg tube 3; when the elastic sleeve 53 disappears due to the pressing force of the lock sleeve 52, the elastic sleeve 53 returns to its original state due to its own elasticity, and releases its pressure against the outer wall of the rear leg tube 3, thereby unlocking the middle leg tube 2 and the rear leg tube 3.

In some embodiments, the sidewall of the elastic sleeve 53 has a plurality of notches 531 extending from the center of the sidewall to the end of the sidewall of the elastic sleeve 53. The provision of the notches 531 in the elastic sleeve 53 is advantageous in improving the elastic deformation performance of the elastic sleeve 53.

In some embodiments, a connecting sleeve 54 is fixedly connected to the outer wall of the lower end of the middle leg tube 2, an adjustment sleeve 55 is screwed to the outer periphery of the connecting sleeve 54, an annular locking groove is provided on the outer wall of the elastic sleeve 53, and a locking block is inserted into the annular locking groove on the inner wall of the lower end of the adjustment sleeve 55. The locking block and the groove side wall of the annular locking groove are fitted together to fix the adjustment sleeve 55 and the elastic sleeve 53 in the axial direction and rotate in the circumferential direction. By rotating the adjustment sleeve 55, the axial position of the elastic sleeve 53 relative to the middle leg tube 2 can be adjusted to better ensure the lock between the elastic sleeve 53 and the locking sleeve 52.

Figure 7 shows a schematic diagram of the second anti-slip structure 8, in which the second anti-slip structure 8 is installed between the inner tube 51 and the rear leg tube 3 to prevent the rear leg tube 3 from slipping out of the inner tube 51. The second anti-slip structure 8 is specifically an anti-slip sheet fixed to the outer wall at the upper end of the rear leg tube 3.

To summarize the above, the extendable support leg 10 of the present invention has a lock control mechanism 6 consisting of a lock ring 61, a planetary gear assembly, and a transmission shaft 62 installed at the upper end of the front leg tube 1. One end of the transmission shaft 62 is inserted into the front leg tube 1 and connected to the first clamp mechanism 4 and the second clamp mechanism 5 through transmission. When adjusting the length of the support leg 10, the lock ring 61 is rotated in one direction, and the lock ring 61 rotates the transmission shaft 62 in the forward direction around its own axial direction through the planetary gear assembly, transmitting the forward rotation of the transmission shaft 62 to the first clamp mechanism 4 and the second clamp mechanism 5, so that the first clamp mechanism 4 releases the movement of the middle leg tube 2 relative to the front leg tube 1, and the second clamp mechanism 5 releases the movement of the rear leg tube 3 relative to the middle leg tube 2, thereby adjusting the length of the support leg 10 to the required length. When adjusted, the lock ring 61 rotates in the opposite direction, and the lock ring 61 rotates the transmission shaft 62 in the opposite direction through the planetary gear assembly, transmitting the reverse rotation of the transmission shaft 62 to the first clamping mechanism 4 and the second clamping mechanism 5, so that the first clamping mechanism 4 prevents the middle leg tube 2 from moving relative to the front leg tube 1, and the second clamping mechanism 5 prevents the rear leg tube 3 from moving relative to the middle leg tube 2, thereby realizing the adjustment of the length of the support leg 10. Compared to the conventional method of adjusting the length of the support leg 10 using a fastener, the method of rotating the transmission shaft 62 using the lock ring 61 and the planetary gear assembly not only has a good locking effect between the three leg tubes of the support leg 10, but also eliminates the need for a fastener protruding from the outside of the leg tube, making it less likely to cause miscontact, and making it easier to store the support leg 10.

Obviously, the above examples are merely examples for the purpose of clarity, and do not limit the embodiments. Those skilled in the art may make other different types of changes or variations based on the above description. It is not necessary and cannot be possible to cover all the embodiments here. And, obvious changes or variations derived thereby still fall within the scope of protection of the present invention.

10, support leg, 20, head element, 1, front leg tube, 2, middle leg tube, 3, rear leg tube, 4, first clamp mechanism, 41, transmission tube, 42, upper lock member, 43, lock body, 44, expansion member, 45, elastic kit, 46, inner friction plate, 5, second clamp mechanism, 51, inner tube, 52, lock sleeve, 53, elastic sleeve, 531, cutout, 54, connecting sleeve, 55, adjustment sleeve, 56, connecting member, 57, stopper rotating disk, 6, lock control mechanism, 61, lock ring, 611, inner convex structure, 62, transmission shaft, 631, sun gear, 632, planetary gear, 64, lower base, 65, upper cover, 66, anti-slip sleeve, 7, first anti-slip structure, 8, second anti-slip structure, 9, tip assembly

Claims (19)

The extendable support leg includes a front leg tube (1), a middle leg tube (2), and a rear leg tube (3) that are arranged in order from the outside to the inside and are extendable and contractible in the axial direction, and the support leg (10) further includes a first clamp mechanism (4) attached between the front leg tube (1) and the middle leg tube (2), and a second clamp mechanism (5) installed between the middle leg tube (2) and the rear leg tube (3);
the lock control mechanism (6) includes a lock ring (61) that is fitted and connected to the upper end of the front-stage leg tube (1) and is installed on the front-stage leg tube (1) so as to rotate in a circumferential direction, and a transmission shaft (62) that is connected to the lock ring (61) in a transmission manner and has one end inserted into the front-stage leg tube (1), wherein when the lock ring (61) rotates in a circumferential direction relative to the front-stage leg tube (1), the lock ring (61) rotates the transmission shaft (62) about its own axial direction, the transmission shaft (62) is operably connected to a first clamp mechanism (4) so as to releasably prevent movement of the middle-stage leg tube (2) relative to the front-stage leg tube (1), and the transmission shaft (62) is operably connected to a second clamp mechanism (5) so as to releasably prevent movement of the rear-stage leg tube (3) relative to the middle-stage leg tube (2). The extendable support leg according to claim 1, characterized in that a lower base (64) is fixedly connected to the upper end of the front leg pipe (1), and the transmission shaft (62) rotates in the circumferential direction and is fixedly connected to the lower base (64) in the axial direction. The extendable support leg according to claim 2, characterized in that the lock ring (61) rotates in the circumferential direction and is fixedly connected to the lower base (64) in the axial direction. The extendable support leg according to claim 2, characterized in that a step structure is provided on the outer periphery of the upper end of the lower base (64), and an inner protruding structure (611) that fits into the step structure is provided on the inner wall of the lock ring (61). The extendable support leg according to claim 4, characterized in that the lock ring (61) and the transmission shaft (62) are connected in a transmission manner via gear meshing. The extendable support leg of claim 5, characterized in that the lock ring (61) is connected in a transmission manner to the transmission shaft (62) via a gear transmission assembly. The extendable support leg according to claim 6, characterized in that an upper cover (65) is fixedly connected to the upper side of the lower base (64), the gear transmission assembly is a planetary gear assembly, the planetary gear assembly includes a sun gear (631) rotatably installed in a central hole of the lower base (64), a plurality of planetary gears (632) located between the upper cover (65) and the lower base (64) and connected to the outer periphery of the sun gear (631) through gear meshing, and a ring gear located on the outer periphery of the plurality of planetary gears (632) and meshing with the plurality of planetary gears (632) to transmit power, the transmission shaft (62) is fixedly connected to the gear shaft of the sun gear (631) and is installed coaxially with the gear shaft of the sun gear (631), and the lock ring (61) is fixedly installed on the outer periphery of the ring gear. The extendable support leg of claim 7, characterized in that the ring gear is fixedly connected to the upper part of the inner convex structure (611). The extendable support leg according to claim 1, characterized in that an anti-slip sleeve (66) is fitted on the outer wall of the lock ring (61), and an anti-slip structure is provided on the outer periphery of the anti-slip sleeve (66). The first clamp assembly includes a transmission tube (41), an upper locking member (42), a locking body (43), and an expansion member (44), the transmission tube (41) is connected to the outer periphery of the transmission shaft (62) and is fixed in the circumferential direction and slides in the axial direction with respect to the transmission shaft (62), the locking body (43) is fixedly connected to the middle leg pipe (2) and is screwed to the outer periphery of the transmission tube (41), and the upper locking member (42) is fixed to the transmission tube (41) and slides in the axial direction with respect to the transmission shaft (62). The extendable support leg according to any one of claims 1 to 9, characterized in that the extension member (44) is fixedly connected to the outer periphery of the front leg tube (1), the extension member (44) is axially fixed to the lock body (43) and located on the outer periphery of the upper lock member (42), and the extension member (44) has a tightened state in which it expands outward under the action of the upper lock member (42) to tighten the inner wall of the front leg tube (1), and a loosened state in which it narrows inward and moves away from the inner wall of the front leg tube (1). The extendable support leg according to claim 10, characterized in that the transmission shaft (62) and the transmission tube (41) have the same cross section, and both cross sections are non-circular. The extendable support leg of claim 10, characterized in that the upper locking member (42) includes a tapered step having an outer tapered inclined surface, the extension member (44) includes at least two mutually independent extension blocks, the inner wall of the extension block has an inner tapered inclined surface, and the outer tapered inclined surface and the inner tapered inclined surface are interlocking. The extendable support leg according to claim 12, characterized in that an elastic kit (45) is provided around the outer periphery of at least two of the expansion blocks, and the elastic kit (45) exerts an inward narrowing force on the at least two expansion blocks. The extendable support leg according to claim 12, characterized in that the outer wall of the extension member (44) is provided with an inner friction plate (46) for abutting against the inner wall of the front leg tube (1). The extendable support leg according to claim 10, characterized in that the second clamping mechanism (5) includes an inner tube (51) fixedly connected to the transmission tube (41) in the axial direction and located inside the middle leg tube (2), a lock sleeve (52) connected to the end of the inner tube (51) remote from the transmission tube (41) and located inside the middle leg tube (2), and an elastic sleeve (53) fitted around the outer periphery of the rear leg tube (3) and partially inserted into the lock sleeve (52) to be fixed to the middle leg tube (2) in the axial direction, and when the lock sleeve (52) and the elastic sleeve (53) move in the axial direction, the elastic sleeve (53) has a clamped state in which it is narrowed inward under the action of the lock sleeve (52) and clamped to the outer wall of the rear leg tube (3), and an unlocked state in which it is separated from the lock sleeve (52) to unlock the rear leg tube (3). The extendable support leg according to claim 15, characterized in that the inner wall of the lock sleeve (52) is provided with an inner inclined guide surface, the outer wall of the elastic sleeve (53) is provided with an outer inclined guide surface, and the inner inclined guide surface and the outer inclined guide surface are fitted together. The extendable support leg according to claim 15, characterized in that a connection sleeve (54) is fixedly connected to the outer wall of the lower end of the middle leg tube (2), an adjustment sleeve (55) is screwed to the outer periphery of the connection sleeve (54), and the elastic sleeve (53) is fixedly connected to the adjustment sleeve (55) in the axial direction. The extendable support leg according to claim 15, characterized in that the side wall of the elastic sleeve (53) has a notch (531) that extends from the center of the side wall of the elastic sleeve (53) to the end of the side wall. The extendable support leg of claim 15, characterized in that a first anti-slip structure (7) is provided between the front leg tube (1) and the middle leg tube (2) to prevent the middle leg tube (2) from sliding out of the front leg tube (1), and a second anti-slip structure (8) is provided between the inner tube (51) and the rear leg tube (3) to prevent the rear leg tube (3) from sliding out of the inner tube (51).

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